Method for matching and tracking workpieces in laser etching operation

ABSTRACT

A method for matching and tracking workpieces in laser etching operation includes generating by the computer a label image that uniquely identifies the workpiece, moving a laser head to the workpiece, setting the laser head to a first power level by a power controller, etching the product image on the workpiece using a laser beam emitted from the laser head, wherein the laser beam is modulated at the first power level in accordance with a product image in a pixel wise fashion across the workpiece, moving the laser head to the label by the transport mechanism, setting the laser head to a second power level by the power controller, etching the label image on the workpiece using a laser beam emitted from the laser head, wherein the laser beam is modulated at the second power level in accordance with the label image in a pixel wise fashion across the label.

BACKGROUND OF THE INVENTION

The present application relates generally to technologies for producingcustomized images on workpieces, and in particular, to a system andmethod for decorating consumer products using laser etching.

In recent years, the popularization of digital media and digitalprinting technologies has created great demands for consumer productsdecorated with customized images. Most of such customized images areprinted by digital printers with colorants such as inks or dyes. Someobjects, however, are not suitable for receiving inks or dyes. Someother objects are aesthetically more appealing if the images aredirectly engraved, carved, or etched on their surfaces without usingcolorants. Such objects can be made of materials such as glass, plastic,wood, stone, metal, laminates, leather or faux leathers, vinyl,composite materials, etc.

Laser etching can produce customized image patterns on objects withoutthe use of colorants. One or more workpieces can be placed in a laseretching apparatus and etched in a batch. In some workflows fordecorating custom products, each item is considered a unique order by anindividual customer. It is difficult to keep track of the workpiecesonce they are removed from the laser etching apparatus using the currentmanufacturing process. While the blank work pieces may have the sameshape and may be made of the same materials, the customized images areusually different and are chosen by different customers. Since thefinished products are often placed on desks and coffee tables fordecorations, it is undesirable to etch or print product tracking numbersor codes directly on the workpieces. Thus, it is easy to mix upworkpieces once they are moved from the laser etching apparatus.

Referring to FIG. 1, currently product tracking labels are printed on ajob ticket 100 (i.e. which can be an 8.5″ by 11″ paper) sheet using aseparate printer such as a laser printer and an ink jet printer.Thumbnail images 110 and 120 that mimic the input digital images areprinted on the job ticket 100 by the laser printer or the ink jetprinter. The thumbnail images 110 and 120 respectively reproduce theimage patterns on the workpieces. In addition, product codes 115, 125that respectively uniquely identify the workpieces (FIG. 1) are alsoprinted respectively adjacent to the thumbnail images 110 and 120. Thejob ticket 100 is then separated to smaller workpiece tracking labelseach corresponding to a workpiece. After the workpieces are moved fromthe laser etching apparatus, the tracking labels are paired up with theworkpieces, to be moved together throughout the rest of themanufacturing steps (e.g. optional in-line processing, up-sale items,packaging, shipping, etc.).

A drawback for the current manufacturing process is that the workpiecetracking labels are printed by different printers, which addscomplexity, labor, and cost to the manufacturing process. Anotherdrawback for the current manufacturing process is that the pairing ofthe workpiece tracking labels and the workpieces can be error-pronebecause the workpieces and their corresponding tracking labels arepaired manually and must be matched together visually.

There is therefore a need for a simpler, less labor intensive, and lowercost solution for manufacturing workpieces using laser etching.

SUMMARY OF THE INVENTION

The present application discloses a system and method that address theabove-described drawbacks in the conventional manufacturing practices.The disclosed system and method are simpler, more accurate and lesserror-prone, and are especially beneficial and provide higher throughputfor etching a large number of workpieces in a batch. Moreover, thedisclosed system and method are implemented by using existing capitalequipment while eliminating the need for separate tracking labelprinters.

In one general aspect, the present invention relates to a laser etchingsystem for forming customized image patterns on workpieces. The etchingsystem includes a computer configured to receive a product image to bereproduced on a workpiece by laser etching and to generate a label imagethat uniquely identifies the workpiece; a laser head that can emit alaser beam; a transport system configured to scan the laser head acrossa workpiece or a label associated with the workpiece; a laser headdriver that can modulate the laser beam in accordance to the productimage or the label image; and a power controller that can set a firstpower level or a second power level of the laser beam at the laser headdriver, wherein the laser head scans across the workpiece to etch theworkpiece at the first power level in pixel-wise fashion to reproducethe product image on the workpiece, wherein the laser head scans acrossa label to etch the label at the second power level in pixel-wisefashion to reproduce the label image on the label.

Implementations of the system may include one or more of the following.The laser etching system can further include an image processorconfigured to produce a composite image comprising a plurality ofproduct images and a plurality of label images associated with theplurality of product images, wherein a plurality of workpieces and aplurality of label holders carrying associated labels can be placed on aplatform. The composite image includes a first image plane and a secondimage plane, wherein the plurality of product images are stored in thefirst image plane, wherein the plurality of label images are stored inthe second image plane, wherein the first image plane and the secondimage plane are respectively associated with the first power level andthe second power level of the laser beam. The power controller can setthe first power level of the laser beam at the laser head driver toreproduce the product images stored in the first image plane on theplurality of workpieces, wherein the power controller can set the secondpower level of the laser beam at the laser head driver to reproduce thelabel images stored in the second image plane on the plurality oflabels. The plurality of product images and the plurality of labelimages can be stored in a common image plane, wherein the powercontroller can dynamically set power level of the laser beam at thelaser head driver before the laser head scans across the plurality ofworkpieces or the plurality of labels. The transport system can scan thelaser head across the platform line by line, wherein the powercontroller dynamically sets power level of the laser beam at the laserhead driver within each line before the laser head scans across one ofthe plurality of workpieces or one of the plurality of labels. The laseretching system can further include a transport controller that cancontrol the transport mechanism to move the laser head over theworkpiece and the label, and to scan the workpiece and the label toallow the product image and the label image to be respectivelyreproduced on the workpiece and the label by laser etching. The laseretching system can further include a platform on which the work pieceand a label holder are placed. The label can be attached to a topsurface of the label holder, where the label image is printed on a topsurface of the label holder. The label can be attached to the topsurface of the label holder by a retainer, or by vacuum suction, or byan adhesive backing on back surface of the label. A plurality ofworkpieces and a plurality of the label holders can be placed in pairson the platform, wherein each of the plurality of label holders isconfigured to hold a label image to track the one of the plurality ofworkpieces in the same pair.

In another general aspect, the present invention relates to a method forlaser etching customized image patterns on workpieces. The methodincludes receiving a product image by a computer, wherein the productimage is to be reproduced on a workpiece by laser etching; generating,by the computer, a label image that uniquely identifies the workpiece,wherein the workpiece and the label are placed over a platform in alaser etching apparatus; moving a laser head to the workpiece by atransport mechanism; setting the laser head to a first power level by apower controller; while scanning the laser head across the workpiece,etching the product image on the workpiece using a laser beam emittedfrom the laser head, wherein the laser beam is modulated at the firstpower level in accordance with the product image in a pixel wise fashionacross the workpiece; moving the laser head to the label by thetransport mechanism; setting the laser head to a second power level bythe power controller; and while scanning the laser head across theworkpiece, etching the label image on the workpiece using a laser beamemitted from the laser head, wherein the laser beam is modulated at thesecond power level in accordance with the label image in a pixel wisefashion across the label.

Implementations of the system may include one or more of the following.The method can further include moving the laser head from a homeposition over the platform of the laser etching apparatus to theworkpiece or the label. The method can further include producing, by animage processor, a composite image comprising a plurality of productimages and a plurality of label images associated with the plurality ofproduct images, wherein a plurality of workpieces and a plurality oflabel holders carrying associated labels are placed on a platform. Thecomposite image can include a first image plane and a second imageplane, wherein the plurality of product images are stored in the firstimage plane, wherein the plurality of label images are stored in thesecond image plane, wherein the first image plane and the second imageplane are respectively associated with the first power level and thesecond power level of the laser beam. The method can further includesetting the first power level of the laser beam at the laser head driverby the power controller to reproduce the product images stored in thefirst image plane on the plurality of workpieces; and setting the secondpower level of the laser beam at the laser head driver by the powercontroller to reproduce the label images stored in the second imageplane on the plurality of labels. The plurality of product images andthe plurality of label images can be stored in a common image plane, themethod further comprising dynamically setting power level of the laserbeam at the laser head driver by the power controller before the laserhead scans across the plurality of workpieces or the plurality oflabels. The method can further include scanning the laser head by thetransport system across the platform line by line; and dynamicallysetting power level of the laser beam at the laser head driver by thepower controller within each line before the laser head scans across oneof the plurality of workpieces or one of the plurality of labels. Thescanning the laser head across the workpiece comprises moving the laserhead, or moving the workpiece, or a combination thereof. The method canfurther include attaching the label to a top surface of a label holderplaced on the platform, wherein the label holder is placed next to thework piece.

These and other aspects, their implementations and other features aredescribed in details in the drawings, the description and the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a job ticket printed by a separate printer in aconventional laser etching workflow.

FIG. 2 is a block diagram of a laser etching system for laser etching aworkpiece in accordance with the present invention.

FIG. 3 is a block diagram of the laser etching system for laser etchinga label for the workpiece in accordance with the present invention.

FIG. 4 illustrates an exemplified laser etching system includingworkpieces and tracking labels in accordance with the present invention.

FIGS. 5A-5C illustrate exemplified configurations how tracking labelsare attached to label holders compatible with the laser etching systemin accordance with the present invention.

FIG. 6 shows a composite image spanning the platform of the disclosedlaser etching apparatus and comprising a plurality of product images anda plurality of associated label images.

FIG. 7 is a flowchart illustrating the operation of the laser etchingsystem in accordance with the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIGS. 2-4, a laser etching system 300 includes a computer310 and a computer memory 320. The computer 310 receives product imagesintended to be reproduced on the workpieces using laser etchingtechnologies. The computer 310 can also generate label images fortracking the workpieces. A controller system 330 is communication withthe computer 310 and is configured to control a laser etching apparatus400. The controller system 330 includes a transport controller 332, apower controller 335, and an image processor 338. In the presentdisclosure, the term product image can include photographic imagesprovided by customers or a service provider, graphic designs, andartwork (including drawings, indicia, text, symbols, etc.) used todecorate final product by laser etching.

The laser etching apparatus 400 includes a laser head driver 340, alaser head 350 and a transport mechanism 360. Workpieces 431-434 andlabel holders 461-464 are placed in pairs on a platform 440 in the laseretching apparatus 400. Each of the label holders 461-464 is associatedwith one of the workpieces 431-434 and is placed next to thecorresponding label holder 461, 462, 463, or 464. The transportmechanism 360 can move the laser head 350 along x-direction 420 and they-direction 425 under the control of the transport controller 332. Thelaser head 350 can be moved over a workpiece 431 (as shown in FIG. 2),or over a label holder 461 (as shown in FIG. 3).

The label holders 461-464 can be made from a solid material and havethicknesses similar to those of the workpieces 431-434. Thus, the labels500 and the top surfaces of the label holders 461-464 are at about thesame height as the top surfaces of the workpieces 431-434. A label canbe attached to or printed on the top surface of each of the labelholders 461-464. In some embodiments, as shown in FIGS. 5A-5C, the label500 can include a peelable self-adhesive backing that is stuck to thetop surface of the label holder 431 (FIG. 5A). Alternatively, the labelholder 431 can include a retainer 520 on its top surface (FIG. 5B). Alabel can be inserted into the retainer 520 to be fixedly held to thetop surface of the label holder 431. A single label can be placed underthe retainer 520 so that is keeps the label stock flat (due to somematerials that may have a ‘curl’). In some embodiments, referring toFIG. 5C, the label holder 431 includes small perforation holes that areconnected to a vacuum system, which can produce a negative pressure tohold a label to the surface of 431.

The laser head 350 can be moved by the transport mechanism 360 under thecontrol of the transport controller 332, to scan the top surfaces of theworkpieces 431-434 (as shown in FIG. 2) as well as the label holders461-464 (as shown in FIG. 3).

The image processor 338 processes the product images in preparation forlaser etching, which can include resizing the product images to thesizes suitable for the dimensions of the workpieces. The product imagescan also be rendered to achieve certain image effects on the particularmaterial type (e.g. glass, stone, wood, metal, etc.) of the workpieces.The image processor 338 also preprocesses the label images for trackingthe workpieces, which can include a thumbnail version of the image and amachine code such as a barcode or 2D matrix code. Both the productimages and the label images are converted to pixel resolution(s)compatible with the scanning resolution of the laser head 350.

The laser head driver 340 provides power and power modulation to thelaser head 350. The power modulation can be based on the pixel values ofthe pre-processed images produced by the image processor 338.

In accordance with the present invention, the power controller 335 isconfigured to set the power level of the laser head driver 340 toaccommodate laser etching on workpieces 431-434 (shown in FIG. 2) orlaser etching on the label holders 461-464 (shown in FIG. 3). Before thelaser head 350 starts etching an image on a workpiece (431-434), thepower controller 335 sets the power level of the laser head driver 340to P_(w), which is selected to etch and remove or fracture materialsfrom the particular material composition of the workpiece (e.g. glass,wood, stone, metal, plastic, etc.), at the specific power level setwhich is consistent with the desired output on the workpiece. In thepresent disclosure, the power level of the laser head driver 340 can bedefined by the maximum, the average, or other relative magnitude for thenext period of laser etching.

After the laser head 350 is position above an image forming area in aworkpiece 431 (shown in FIG. 2), the laser head 350 emits a laser beamthat is modulated by the laser head driver 340 in accordance with theproduct image. The laser beam selectively heats and burns certainlocations of the workpieces 431-434 in a pixel wise fashion, andfractures or removes materials off the workpiece 431 to form an imagepattern 451 (or 452) that mimics the product image is created on the topsurfaces of the workpiece 431.

Before the laser head 350 starts etching an image on a label on a labelholder (461-464), the power controller 335 sets the power level of thelaser head driver 340 to P_(L). In many situations, especially when thelabel is formed by a sheet of paper, P_(L) is lower than P_(w). In otherwords, it takes less power to burn marks on paper than on the solidmaterials that forms the workpiece.

After the laser head 350 is positioned above a label holder 461 (shownin FIG. 3), the laser head 350 emits a laser beam that is modulated bythe laser head driver 340 in accordance with a label image. The laserbeam selectively heats and makes burn marks at different locations ofthe label in a pixel wise fashion, to form a label image. Similar tothose shown in FIG. 2, a label image can include a thumbnail version ofthe product image, which is reproduced on the workpiece, and a machinecode that uniquely identifies the workpiece.

It should be noted that the transport controller can produce relativemovements between the transport mechanism and the workpieces and thelabels for scanning and reproducing product and label images on theworkpieces and the labels. Such relative movements can be produced bymoving the laser head, or the workpieces and the labels, or acombination thereof. Thus, in some configurations, the transportmechanism 360 can also move the workpiece 431 and the label holder 461(directly or by moving a platen or the platform on which the workpiece431 and the label holder 461 are placed).

In some embodiments, the image processor 338 combines all of the data(e.g. artwork, image, label image & barcode) for workpiece decorationand workpiece tracking as a single composite image. Referring to FIGS.2-6, a single composite image 600 includes an origin 601 and covers mostof the working area in the platform 440. The single composite image 600includes product images 651-654 and label images 671-674. The productimages 651-654 are used to produce image patterns (e.g. 451, 452) on thework pieces 431-434. The label images 671-674 include product trackinginformation and are to be reproduced on the tracking labels on the labelholders 461-464. The image patterns and label image can be laser etchedrespectively on workpieces and tracking labels in one batch operation.These product images 651-654 and the label images 671-674 arerespectively registered to the physical positions of the workpieces431-434 and their respectively associated label holder 461-464. Thespaces outside of the workpieces 431-434 and the label holders 461-464correspond to the blank areas in the composition image 600 that do notreceive laser etching. The transport controller 332 commands thetransport mechanism 360 to move the laser head 350 to a known homeposition within the platform 440. The home position corresponds to theorigin 601 in the composite image 600. The laser etching patterns arethus correctly aligned to the workpieces 431-434 and label holders461-464.

In some embodiments, the product images 651-654 and the label images671-674 are contained in separate image planes with a first image planeassociated with power level P_(w) and a second image plane associatedwith power level P_(L). The laser head driver 340 can be moved andcontrolled to etch one image plane at a time. The power controller 335automatically sets the laser head driver 340 to power level P_(w) beforelaser etching of the first image plane, and sets the laser head driver340 to power level P_(L) before laser etching of the second image plane.

In some embodiments, the power levels P_(w) and P_(L) of laser etchingcan be represented by code values within a same image plane in thecomposite image 600. For example, if power levels of the laser head 350is quantized to 0-255 levels with high code values associated withhigher laser power, P_(w) can correspond to the level of 220 for certainworkpiece material such as glass; P_(L) can correspond to the level of50 for track label material such as certain type of pulp or syntheticpaper. The power controller 335 automatically sets the power level ofthe laser head driver 340 as the laser head driver 340 is moved to areasoccupied by the workpieces 431-434 and the label holders 461-464.

The presently disclosed laser etching system can be operated in one ormore of the following steps: referring to FIG. 7, product images arereceived by a computer (step 710). Each product image is to bereproduced on a workpiece by laser etching. Label images are generatedby the computer (step 720). Each label image uniquely identifies aworkpiece. One or more workpieces and labels are placed on a platform ina laser etching apparatus. A laser head is first stationed at the homeposition over the platform of the laser etching apparatus, and thenmoved over a first workpiece by a transport mechanism (step 730). Thepower level of the laser head is set at P_(w) by a power controller at alaser head driver (step 740). The laser head is scanned across theworkpiece. A first product image is etched on the first workpiece by amodulated laser beam emitted from the laser head (step 750). Asdescribed above, the laser beam is modulated in accordance with theproduct image in a pixel wise fashion across the workpiece. The laserhead is moved over a first label on a first label holder associated withthe first workpiece (step 760). The power level of the laser head is setby the power controller at P_(L) at the laser head driver (step 770).The laser head is scanned across the label. A first label image isetched on the first label by a laser beam emitted from the laser head(step 780). The laser beam is modulated in accordance with the labelimage in a pixel wise fashion across the label.

Steps 730-780 are repeated to etch product images on other workpiecesand etch label images on labels associated with respective workpieces(step 790). As discussed above, in some embodiments, the product images(and associated image patterns) and the label images can be stored inseparate image planes in a single composite image with the origin ofcomposite image corresponding to the home position. Steps 730-750 can berepeated with the power level set once at the P_(w) level for the imageplane for product images. Similarly, steps 760-780 can be repeated withthe power level set once at the P_(L) level for the image plane forlabel images.

In some embodiments, the power levels P_(w) and P_(L) of laser etchingcan be represented by code values within a same image plane in thecomposite image. Steps 730-780 are alternately repeated to etch productimages and label images on different pairs of workpieces and labels.Specifically, the power level can automatically be set to an appropriatelevel along each scan line (along the x direction in FIG. 4) as thelaser head is moved by the transport mechanism into a workpiece area ora label area. After one scan line is finished, the laser head is moved(in the y-direction in FIG. 4) by the transport mechanism to the nextscan line. Lines without etching operations (e.g. with all zero codevalues) can be skipped and the laser head is moved in the y-directionuntil a line with etching data is found.

Only a few examples and implementations are described. Otherimplementations, variations, modifications and enhancements to thedescribed examples and implementations may be made without deviatingfrom the spirit of the present invention. For example, the discloseddeposition apparatus is compatible with other types of mechanism forholding a label onto a label holder. In some cases, the label holdersthemselves can serve as labels. Moreover, the transport mechanism can beimplemented in other configurations to create relative movements betweenthe laser head across and the workpieces and labels on the platform. Forexample, instead of moving the laser head, the workpieces and labels canbe moved by the transport mechanism to bring individual workpieces andlabels to the laser head.

Furthermore, the laser head can move over workpieces and labels in a waythat the power level is modulated to different power levels for eacharticle but the laser moves in a continuous x-direction motion acrossthe entire platform, advancing one line at a time in the y-direction. Inaddition, the same applies to a laser system that etches a cylindricalworkpiece and label system where the laser head only moves in thex-direction but the cylindrical articles are rotated one line at a timein the y-direction, centered beneath the laser head.

What is claimed is:
 1. A method for matching and tracking workpieces inlaser etching operation, comprising: receiving a product image by acomputer, wherein the product image is to be reproduced on a workpieceby laser etching; generating, by the computer, a label image thatuniquely identifies the workpiece, wherein the workpiece and the labelare placed over a platform in a laser etching apparatus; moving a laserhead to the workpiece by a transport mechanism; setting the laser headto a first power level by a power controller; while scanning the laserhead across the workpiece, etching the product image on the workpieceusing a laser beam emitted from the laser head, wherein the laser beamis modulated at the first power level in accordance with the productimage in a pixel wise fashion across the workpiece; moving the laserhead to the label by the transport mechanism; setting the laser head toa second power level by the power controller; while scanning the laserhead across the label, etching the label image on the workpiece using alaser beam emitted from the laser head, wherein the laser beam ismodulated at the second power level in accordance with the label imagein a pixel wise fashion across the label; and pairing the label with theworkpiece to track the workpiece.
 2. The method of claim 1, furthercomprising: moving the laser head from a home position over the platformof the laser etching apparatus to the workpiece or the label.
 3. Themethod of claim 1, further comprising: producing, by an image processor,a composite image comprising a plurality of product images and aplurality of label images associated with the plurality of productimages,
 4. The method of claim 3, wherein the composite image includes afirst image plane and a second image plane, the method furthercomprising: storing the plurality of product images in the first imageplane; and storing the plurality of label images in the second imageplane, wherein the first image plane and the second image plane arerespectively associated with the first power level and the second powerlevel of the laser beam.
 5. The method of claim 4, further comprising:setting the first power level of the laser beam at the laser head driverby the power controller to reproduce the product images stored in thefirst image plane on the plurality of workpieces; and setting the secondpower level of the laser beam at the laser head driver by the powercontroller to reproduce the label images stored in the second imageplane on the plurality of labels.
 6. The method of claim 3, wherein theplurality of product images and the plurality of label images are storedin a common image plane, the method further comprising: dynamicallysetting power level of the laser beam at the laser head driver by thepower controller before the laser head scans across the plurality ofworkpieces or the plurality of labels.
 7. The method of claim 6, furthercomprising: scanning the laser head by the transport system across theplatform line by line; and dynamically setting power level of the laserbeam at the laser head driver by the power controller within each linebefore the laser head scans across one of the plurality of workpieces orone of the plurality of labels.
 8. The method of claim 3, wherein theworkpiece and the label are positioned on the platform with a gap inbetween, wherein the composite image includes a blank area correspondingto the gap between the workpiece and the label.
 9. The method of claim1, wherein the step of scanning the laser head across the workpiececomprises: moving the laser head, or moving the workpiece, or acombination thereof.
 10. The method of claim 1, further comprising:placing a label holder next to the work piece on the platform; andattaching the label to a top surface of the label holder.